The present invention relates in general to smelt processing equipment, and in particular to a new and useful shatter jet mechanism for breaking a smelt stream.
Shatter jets are used on chemical recovery furnaces to shatter the smelt stream as it exits the furnace through the smelt opening and the smelt spout. The smelt stream must be shattered into droplet-size materials to prevent a smelt-water explosive reaction when contact is made with the green liquor in the dissolving tank. The shatter medium is usually steam although compressed air is occasionally used.
Shatter jet mechanisms consist of a horizontal pipe which may be rotated about its centerline axis with a tee section and nozzle or nozzles in the center, arranged so that directional control of the nozzle is accomplished by rotating the pipe. A length of pipe between the tee and the nozzle produces a fixed arc of nozzle positions usually maintained in a given position by a notched handle. Some shatter jets are arranged with the main pipe in a vertical position so that the nozzle has a horizontal arc.
The trajectory of the smelt stream as it flows off the end of the smelt spout is variable and depends on the volume of smelt flow, the smelt temperature and other operating conditions. Directional control of the shatter jet nozzle to meet the variable trajectory is important to assure the maximum efficiency in shattering the smelt stream into droplets.
Of equal importance is the directional control of the resultant shattered smelt droplets toward the opening in the dissolving tank. Impingement of the smelt droplets on adjacent surfaces should be avoided since the semi-cooled smelt has a tendency to stick to all surfaces and resuts in a buildup which must be manually removed. Large deposits may remain hot enough to cause an explosion when they are removed and fall into the dissolving tank.
U.S. Pat. No. 2,967,758 to Thornson discloses an apparatus for disintegrating and dispersing a molten smelt stream. Also see U.S. Pat. No. 3,122,421 to Gettle; U.S. Pat. No. 4,421,596 to Hogberg; U.S. Pat. No. 2,007,799 to Gloersen; and U.S. Pat. No. 4,280,982 to Shindome et al. All these references show the use of jets for breaking up a smelt stream.
U.S. Pat. No. 2,518,239 to Leigh is also relevant for showing a spray nozzle mounting and oscillating mechanism used in chemical recovery furnaces.